The clinical core is comprised of 3 major tasks: treatment planning; (2) development of simulator and portal imaging network (SPIN); (3) development of interventional therapy with CT (CT-guided treatment. (1) Treatment Planning: The treatment planning core is responsible for planning approximately 65 patients per year for the prostate and lung dose escalation studies. Prostate treatment will generally involve intensity modulation delivered with dynamic multileaf-collimator (DMLC). Lung treatments will be done in deep inspiration breath-hold (DIBH). The core will also be responsible for the safe and accurate delivery of these treatments and will participate in the analysis. In additoin, the core will do acceptance testing and on-going QS on all software developed in Projects II-IV that is used to plan and/or treat patients. Finally, all documentation of patient records will be maintained by the core. (2) SPIN: This client-based server network will be enhanced tomeet the needs of Research Projects I- IV. It will provide integration of the 3D planning system with SPIN which will be used by Research Project I patients. It will provide on-line analysis for measuring patient setup error, verification of DMLC treatments, portal imaging verification of DIBH treatments, and interventional changes required with CT- guided treatment. Finally, it will expand it physical resources to meet increased QA needs. (3) CT-guided treatment: Tools will be developed for Research Project IV in which it is proposed to study treatments in which a patient is scanned prior to treatment, the change in patient~s setup required to register the prostate and treatment field is determined from the CT scans, and the patient is transported to and positioned on the treatment unit in the corrected position. The core will: (a) develop a method to immobilize the patient in a rigid device with licalization markers, (b) implement and test software tools (manual and possibly automatic) to determine the change in positoin required to register the tumor and treatment field, (c) develop a method to transport the patient smoothly and CT unit to the treatment machine and accurately position the patient.